Fluval U3 Or U4

[Fantail_John]

Can anyone tell me will my filter do the job for a 28 Imperial gallons tank, it is a aqua-flow 200 don't know much about them but it puts though 400 litres = 87.987663 Imperial gallons a hour tops. up to now i have 5 platy's.

John

 

[waterdrop]

Well, if the filter is pulling through 88 IG per hour and the tank is 28 IG then you will only be getting 3 turnovers per hour.

Whether this is enough is a judgement call. We usually recommend 5x turnover, so 3 is low. The problem with taking any one stat though and thinking about it in a blanket terms is that there are other factors. In this case the other factor is how often and well you perform gravel-clean-water-changes. Do a good job of that and the tank could get by with less flow rate.

~~waterdrop~~

 

[Fantail_John]

Well, if the filter is pulling through 88 IG per hour and the tank is 28 IG then you will only be getting 3 turnovers per hour.

Whether this is enough is a judgement call. We usually recommend 5x turnover, so 3 is low. The problem with taking any one stat though and thinking about it in a blanket terms is that there are other factors. In this case the other factor is how often and well you perform gravel-clean-water-changes. Do a good job of that and the tank could get by with less flow rate.

~~waterdrop~~

Been thinking it over and thought i will buy a bigger filter, before i do stock with more fish. so would a Fluval 4 internal do the job for a 28 gallon tank 1000 liters (219 gallons PH) or would it be to strong for the tank? and is this filter any good your thoughts please.

John

 

[waterdrop]

All the Fluval internals are highly recommended by many of our members. Of course that's the biggest one and the question does arise as to whether the flow rate might be a bit strong for your tank. I could not find an actual flow rate spec at Hagan, but your tank volume is at the very bottom of this filters range.

The queston also arises as to whether you want a filter that large to be internal and taking away that much space from your aquascape. I have a smaller tank than yours and use a larger external cannister filter with an external heater just so that no gear will be in the tank (or at least just the intake tube and spraybar. I'm not sure how the cost comparisons would work out but Tetratec externals sell for pretty competitive prices in the UK I understand. Probably Rena and Eheim would be more expensive than the Tetratecs. But there might be an external cannister that would match up with your tank size better than that U4.

~~waterdrop~~

 

[Fantail_John]

All the Fluval internals are highly recommended by many of our members. Of course that's the biggest one and the question does arise as to whether the flow rate might be a bit strong for your tank. I could not find an actual flow rate spec at Hagan, but your tank volume is at the very bottom of this filters range.

The queston also arises as to whether you want a filter that large to be internal and taking away that much space from your aquascape. I have a smaller tank than yours and use a larger external cannister filter with an external heater just so that no gear will be in the tank (or at least just the intake tube and spraybar. I'm not sure how the cost comparisons would work out but Tetratec externals sell for pretty competitive prices in the UK I understand. Probably Rena and Eheim would be more expensive than the Tetratecs. But there might be an external cannister that would match up with your tank size better than that U4.

~~waterdrop~~

Thank's for your advice about the externals but i have not the room to place next to my tank so what would you recommend for an internal you say that the fluval u4 is to big for the flow so would a u3 do or any that you would recommend that gives 5 times turn out PH.

John

 

[Twinklecaz]

The U2 does 400l per hour (so it's fine for my 60l) so yeah maybe the U3 for you?

 

[waterdrop]

It clearly seems the decision is between the U3 and the U4 for you then. I try to limit my advice on the modern internals as I don't have first-hand experience with them and lots of other members do. I'm not sure there's a right or wrong. I could imagine different of our members advising you in both directions. Higher flow as various advantages of forcing more debris up off the substrate and subsequently filtering it, leaving less for you to vacuum out in the weekly changes. Higher flow results in fewer trace ammonia pockets that can trigger algae, so it helps you in your balancing war against algae. Higher flow mixes the water to a more even temperature all over the tank.

But higher flow can make your fish look like they are in the washing machine. Sometimes it can be difficult to redirect the output somewhere that doesn't knock the fish and plants around once you decide the flow is too strong.

Perhaps give it a bit more time and we'll see if some U3 or U4 owners with similar tank sizing will step up and comment??

~~waterdrop~~

 

[Fantail_John]

It clearly seems the decision is between the U3 and the U4 for you then. I try to limit my advice on the modern internals as I don't have first-hand experience with them and lots of other members do. I'm not sure there's a right or wrong. I could imagine different of our members advising you in both directions. Higher flow as various advantages of forcing more debris up off the substrate and subsequently filtering it, leaving less for you to vacuum out in the weekly changes. Higher flow results in fewer trace ammonia pockets that can trigger algae, so it helps you in your balancing war against algae. Higher flow mixes the water to a more even temperature all over the tank.

But higher flow can make your fish look like they are in the washing machine. Sometimes it can be difficult to redirect the output somewhere that doesn't knock the fish and plants around once you decide the flow is too strong.

Perhaps give it a bit more time and we'll see if some U3 or U4 owners with similar tank sizing will step up and comment??

~~waterdrop~~

Thank's for you reply

It gets so confusing lol but no laughing matter for the fish, all people i have talk to say i need 5 times the hourly flow on my tank and now trying to do this to the best i can now we have people saying the flow might be to fast? so please people can you help me regarding the U3 or U4 for a 28 gallon tank

John

 

[waterdrop]

I agree! People! Where are you.

 

[OohFeeshy]

Both types of Fluval (+ and U) are adjustable, so with the + you can actually lower the flow, with the U you can put it on the spraybar setting.

Really, get the biggest you can, don't rely on what the manufacturer says because quite often the tank size reccomended is larger than I think the filter can support. However, the main issue with the Fluvals is size. A 4+ isn't really an option unless you've got an 18" high tank, for example. Not sure how big the U4 is but I'd imagine it will be quite a squeeze in a 15" high tank. Out of the two, the U's are less obtrusive and you've got ceramic media, plus cleaning is a tonne easier.

 

[Twinklecaz]

You can lay the U's on the substrate though if you want can't you? So maybe that's an option?

I'm thinking of doing it while I'm cycling coz obv the water level keeps dropping and the valve at the top needs to be above the water line (had to move the filter down once already). Actually that's a point.....if you lay it on the botton what happens to the valve then? Sorry i can't think of it's name, it begins with V.

 

[OohFeeshy]

Venturi? If it is, then you don't need it anyway. They don't need to be completely submerged. You can put them in whatever position you like, I suppose, but also remember the lid is at the top so if it's at the bottom, taking the media out will be a right pain in the proverbials.

 

[Twinklecaz]

Ha true. I need it to be submerged because when the water line went down it made it start to bubble flow (I don't have it set to do that, just agitate) and it's noisy and it's in my bedroom!

 

[Fantail_John]

Both types of Fluval (+ and U) are adjustable, so with the + you can actually lower the flow, with the U you can put it on the spraybar setting.

Really, get the biggest you can, don't rely on what the manufacturer says because quite often the tank size reccomended is larger than I think the filter can support. However, the main issue with the Fluvals is size. A 4+ isn't really an option unless you've got an 18" high tank, for example. Not sure how big the U4 is but I'd imagine it will be quite a squeeze in a 15" high tank. Out of the two, the U's are less obtrusive and you've got ceramic media, plus cleaning is a tonne easier.

Thank's

I think i'll go with the fluvel U4 as it should fit ok in my tank as the hight is just under 12inch's 30 CM, but be taking out the carbon pads and if is ok replace by other sponge pads. So in the next few weeks i will see if any more advive comes and see what happens.

Thank's again
John